Support frame vehicle restraints

ABSTRACT

A vehicle restraint restrains a vehicle at a loading dock by engaging a rail that is part of the vehicle&#39;s support frame, wherein the rail is normally used for adjusting the position of the vehicle&#39;s rear wheels. In a preferred embodiment, the restraint includes an adjustable-length arm attachable between the vehicle and the loading dock. The arm includes a retractable or removable pin that engages one of a series of holes in the rail or releasably engages some feature of the loading dock. In some examples, the restraint clamps onto the rail, particularly if the rail has no available open holes for a pin to be inserted. In some cases, the restraint also provides the vehicle with vertical support.

FIELD OF THE DISCLOSURE

The subject invention generally pertains to restraining vehicles atloading docks and more specifically to restraints that engages aweight-supporting rail of a vehicle support frame.

BACKGROUND

When a truck, trailer, or some other vehicle is parked at a loadingdock, often some type of vehicle restraint is used to keep the truckfrom inadvertently moving away from an elevated platform of the dock.This allows forklifts and other material handling equipment to safelytravel between the dock platform and the truck for the purpose ofloading or unloading the truck's cargo.

There are a variety of vehicle restraints available that can beinstalled at a loading dock for engaging a truck's RIG (Rear ImpactGuard), also known as an ICC bar. An ICC bar is a beam that extendshorizontally across the rear of a truck, just below the truck bed. Itsprimary purpose is to prevent an automobile from under-riding the truckin a rear-end collision. However, not all trucks have an ICC bar thatcan be readily engaged by an ICC-style restraint. In those cases, awheel restraint might be used for blocking one or more of the truck'swheels.

Perhaps the most common wheel restraint is simply a wheel chock thatwedges between the driveway and the underside of the wheel. However,wheel chocks often slip out of position on driveways that are slipperydue to oil, rain, ice, sand, gravel, or dirt. Sometimes wheel chockswedge so tightly under the wheel that they become very difficult toremove. Trucks have also been known to drive completely up and over awheel chock. Additionally, wheel chocks are often loose items that arenot permanently attached to the loading dock area, so they tend to getmisplaced.

Some known restraints include powered wheel restraints that travel alonga track. However, such wheel restraints cannot always be readilyinstalled at loading docks that might have a drain or some otherdriveway irregularity situated where the track is to be installed.Moreover, powered wheel restraints are relatively expensive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view a vehicle restraint in a holding position.

FIG. 2 is a perspective view of the vehicle restraint of FIG. 1 butshowing the restraint in a release position.

FIG. 3 is a perspective view of another vehicle restraint in a holdingposition.

FIG. 4 illustrates another example vehicle restraint described hereinshown in a release position.

FIG. 5 illustrates the example vehicle restraint of FIG. 4 shown in aholding position.

FIG. 6 illustrates yet another example vehicle restraint shown in arelease position.

FIG. 7 illustrates the example vehicle restraint of FIG. 6 shown in aholding position.

FIG. 8 illustrates yet another example vehicle restraint describedherein.

FIGS. 9 & 10 illustrate a side view and a schematic illustration,respectively, of the example vehicle restraint of FIG. 8 shown in arelease position.

FIGS. 11 & 12 illustrate a planar view and a side view, respectively, ofthe example vehicle restraint of FIGS. 8-10 shown in a holding position.

FIG. 13 is an example schematic illustration of the example vehiclerestraint of FIGS. 11 & 12.

DETAILED DESCRIPTION

FIGS. 1 and 2 show a restraint 10 for restraining a vehicle 12 at aloading dock 14. Restraint 10 is shown in a holding position in FIG. 1and is shown in a release position in FIG. 2. In the holding or engagedposition, restraint 10 helps hold vehicle 14 adjacent a dock face 16 sothat cargo can be safely conveyed on and off of vehicle 12. In somecases, a conventional dock leveler 18 can be used to facilitate theloading and unloading operations. An upper section of vehicle 12 isshown in phantom lines to more clearly show restraint 10 in the holdingposition.

Restraint 10 includes an elongate member 20 having an anchored end 22pivotally coupled to an anchor 24 that may be installed at a generallyfixed location. An engagement end 26 of elongate member 20 is adapted toselectively attach and release a rail 28 or some other supporting framestructure of vehicle 12.

Rail 28 is preferably interposed laterally between a set of wheels 30 sothat the restraining force exerted on vehicle 12 is more evenly (e.g.,centrally) applied, rather than pulling on the vehicle's 12 outer sides.In this manner, because rail 28 is “laterally” interposed between wheels30, rail 28 may be at an elevation higher than the uppermost surface ofwheels 30. This is particularly advantageous because a restrainedvehicle attempting to pull away from the dock can generate significantstrain in the vehicle's frame. To help reduce the strain in certainareas of the vehicle's frame (e.g., where the ICC bar connects to theframe), rail 28 or the restraint's engagement therewith is preferably ata connection or connection point that is higher than the wheels'rotational axis and nearly inline with the bottom of the truck/trailerbed, in contrast to a typical ICC bar that is well below thetruck/trailer bed.

Restraint 10 is particularly advantageous for use with rails (e.g., rail28 in FIGS. 1-2) that are commonly known as “bogey rails.” A bogey railis a frame member that supports the bed of a truck or trailer andincludes a plurality of holes 32. Holes 32 allows a rear axle assembly34 to be slidingly adjusted and coupled in position to rail 28 via a pin36 that fits through a flange 38 of axle assembly 34 and one of holes32. Adjusting the position of axle assembly 34 to a forward position canimprove the vehicle's maneuverability in town or on smaller streets, anda more rearward position can improve the vehicle's stability over thehighway. In some cases, the axle's position is adjusted to more evenlydistribute the weight carried by the vehicle's wheels.

Although the actual design of restraint 10 may vary, in some examples,engagement end 26 connects to rail 28 via a clevis connection and aremovable pin 40. To accommodate some angular or lateral misalignmentbetween rail 28 and anchor 24, there is clearance (e.g., preferablyample play) between rail 28 and the clevis of engagement end 26. Inother examples, elongate member 20 includes a pivotal joint orlimited-movement slip joint near engagement end 26, thereby providingend 26 with some articulation or limited movement so that pin 40 can bereadily aligned with at least one hole 32. A similar result can beachieved by providing a slot 66 at pin 40 or providing any othersuitable pin/slot connection between engagement end 26 and anchor 24(e.g., a slot 66′ of FIG. 3). Such a pin/slot or equivalent connectionalso makes it easier to disengage elongate member 20 for releasingvehicle 12

Additionally or alternatively, elongate member 20 comprises a pair oftelescoping members 20 a and 20 b for further adjustment. A removablepin 42 selectively inserted in one of a series of holes 44 in member 20b provides elongate member 20 with an adjustable length.

To facilitate aligning engagement end 26 to rail 28, anchor 24preferably comprises a universal joint 46 that allows elongate member 20to pivot (e.g., in a vertical and/or horizontal direction). The pivotalmotion enables elongate member 20 to pivot between the positions shownin FIGS. 1 and 2.

In some examples, restraint 10 includes a sensor 48 (e.g., limit switch,proximity switch, etc.) that detects whether restraint 10 is in itsholding position of FIG. 1 or its release position of FIG. 2. Sensor 48transmits or sends a signal to one or more indicator signals 50accordingly. Examples of signal 50 include, but are not limited to,indoor or outdoor red and green lights. Sensor 48 is shown near anchor24 to detect the angular position of elongate member 20. However, inother examples, sensor 48 may be positioned in any other suitable mannerto detect the position or state of engagement of restraint 10.

For some vehicles, the position of the wheels is nonadjustable. FIG. 3,for instance, shows a vehicle 52 with wheels 30 installed at a fixedposition. In this case, vehicle 52 includes a structural rail 54 thatdoes not have a series of holes for adjustment. So, instead of a pinengaging a hole in the rail, a restraint 56 includes a clamp 58 that mayfrictionally engage or grip rail 54. Clamp 58, for example, may includea screw 60 that screws into a threaded hole in an engagement end 62 ofan elongate member 64 that is otherwise similar to member 20.

In other examples, if a vehicle such as, for example, vehicle 12 ofFIGS. 1-2, were to arrive at the dock, screw 60 may be operated toextend into one of holes 32, whereby screw 60 rather than pin 40 wouldextend into hole 32. In yet other examples, for vehicles with railshaving no adjustment holes, one or more holes comparable to hole 32could be produced in the rail solely for the purpose of being engaged byrestraints 10 or 56. Such holes may be retrofit to existing vehiclesand/or may be created when the vehicle is manufactured or at any timethereafter.

In other examples, such as where a vehicle's wheels have been adjustedto their fully back position, thus leaving no open holes behind thewheels, restraint 10 or 56 may be relocated to a position in front ofwheels 30 to engage rail holes in that area. The repositioning ofrestraint 10 or 56 may be done by moving anchor 24 to the new forwardlocation and fastening anchor 24 to a surface generally in front ofwheels 30 such as, for example, a driveway surface. Alternatively, asecond anchor may be permanently installed at the more forward location,and elongate member 20 or 64 may be selectively attached to and releasedfrom the anchor located at the most suitable location.

Alternatively, elongate member 20 or 64 could be attached to and carriedby vehicle 12 even as vehicle 12 travels over the road. If engagementend 26, for example, is left fastened to rail 28, anchored end 22 couldselectively attach to and release from anchor 24 to respectivelyrestrain and release vehicle 12. In this manner, another aspect of theexamples described herein is illustrated in FIGS. 4 and 5. FIG. 4 showsa restraint 70 comprising a vehicle-carried elongate member 72 in arelease position, and FIG. 5 shows restraint with elongate member 72 ina holding position.

In this particular example, elongate member 72 has a proximal end 74pivotally coupled either to rail 28 or to some other suitably surface orcomponent of vehicle 12. The pivotal mounting of member 72 enables adistal end 76 of member 72 to be selectively raised or lowered. Whenmember 72 is raised to the release position of FIG. 4, vehicle 12 isfree to travel over the road while carrying member 72. A clip 78 onvehicle 12 can be used to help hold or restrain member 72 when in itsrelease position.

To inhibit or prevent vehicle 12 from moving forward away from a loadingdock 80, member 72 is lowered to the holding position of FIG. 5 so thatdistal end 76 engages some anchor point of dock 80. Examples of such ananchor point include, but are not limited to, a wheel guide rail 82, anelevated protrusion or obstruction mounted to a driveway 84 of dock 80,a detent associated with driveway 84, a frictional or toothed track ondriveway 84, and/or the driveway surface itself. In the case where wheelguide rail 82 provides the anchor point, rail 82 preferably includes aseries of detents 86 that enable distal end 76 of member 72 to engagerail 82 more securely than what might otherwise be achieved withfriction alone.

To accommodate incidental movement of vehicle 12 as the vehicle is beingloaded or unloaded of cargo, or to adjust for variations in the distancebetween proximal end 74 and a certain anchor point 86, the length ofelongate member 72 can be made adjustable (e.g., to a certain limiteddegree). In some cases, for example, member 72 includes twospring-loaded telescoping arms 72 a and 72 b that provide suchadjustment or tolerance to limited vehicular movement. The examplesdescribed herein are not limited to telescoping arms, but may includeany other suitable length-adjustable mechanism(s) that provideadjustment of elongate member 72.

The pivotal deployment of a vehicle-carried restraint may be manually orunder power. FIGS. 6 and 7, for example, show a restraint 88 comprisinga power actuator 90 (e.g., hydraulic cylinder, pneumatic cylinder,linear motor, etc.) that pivots an elongate member 92 between itsrelease position of FIG. 6 to its holding position of FIG. 7. To inhibitvehicle 12 from moving forward away from the dock, a distal end 94 ofmember 88 can be pinned or otherwise temporarily connected to a rail 96that is mounted to the dock's driveway 84. To help align distal end 94to a selected hole 98 in rail 96, member 92 can include a lengthadjustment feature 100 such as, for example, a limited telescopingconnection. By forcibly powering member 92 down to its holding position,member 92 can also be used to help prevent or block the verticalmovement of vehicle 12 as the vehicle is loaded or unloaded of cargosince in this configuration it acts as a rigid brace preventing suchvertical movement.

FIGS. 8-13 show an alternate vehicle restraint 102 where vertical andhorizontal movement of vehicle 12 is restricted by one or more hydrauliccylinder assemblies 104 that expand vertically between driveway 84 andrail 28 (or some other comparably rigid (e.g., strong) part of vehicle12). To release vehicle 12, cylinder assembly 104 retracts avehicle-engaging upper ram 106 and a driveway-engaging lower ram 108.FIGS. 8-10 show restraint 102 retracted to a release position, and FIGS.11-13 show restraint 102 expanded to a holding position. Arms 110pivotally couple cylinder assemblies 104 to dock 112 so that whencylinders 104 are retracted, arms 110 enable cylinders 104 to pivot(e.g., be swung out) from underneath vehicle 12. Moving cylinders 104beyond the width of vehicle 12 can prevent a low hanging rear impactguard 114 of vehicle 12 from striking restraint 102 as the vehicle 12enters or departs the loading dock 112.

In some examples, lower ram 108 fits telescopically within upper ram106, and a tension spring 116 can be used to draw rams 106 and 108together, as shown in FIG. 10. The two rams 106 and 108 fit slidinglywithin an outer sleeve 118, which in turn is supported in a cantilevermanner by arm 110. Upper ram 106 includes a collar 120 that retains ram106 with sleeve 118 and prevents ram 106 from dropping out from withinsleeve 118.

To extend rams 106 and 108 from their positions of FIG. 10 to that ofFIG. 13, a line 122 feeds pressurized hydraulic fluid 124 into anexpandable chamber 126 defined by rams 106 and 108. The weight of upperram 106 acts against its extension, and the weight of lower ram 108urges the extension of ram 108, thus the pressurized fluid 124 from line122 causes lower ram 108 to extend first. After lower ram 108 engagesdriveway 84, upper ram 106 extends to engage vehicle 12 until cylinderassembly 104 expands between driveway 84 and the underside of vehicle12, as shown in FIG. 13.

Although the hydraulic system for pressurizing cylinder assembly 104 canbe provided by various means well known to those of ordinary skill inthe art, restraint 102 includes a hydraulic system 128 comprising ahydraulic pump 130, a control valve 132, a check valve 134, and ahydraulic fluid reservoir 136 provided by arm 110 itself. Item 138 is afill cap for reservoir 136. Pump 130 is schematically illustrated torepresent any suitable means for pressurizing fluid 124. Examples ofpump 130 include, but are not limited to, an electric pump, ahand-operated pump, and an air-over-oil system where fluid 124 can bepressurized by injecting high-pressure air (e.g., 100 psi) intoreservoir 136, etc.

Control valve 132 can be a three-way, two-position valve that ismanually actuated (or solenoid actuated) with spring return. In thenormally retracted position of FIG. 10, pump 130 is inactive, and line122 and valve 132 convey hydraulic fluid 124 from within chamber 126 toreservoir 136, wherein fluid 124 moves under the impetus of spring 116drawing rams 106 and 108 together. To extend cylinder assembly 104,valve 132 is manually actuated to the position shown in FIG. 13, andpump 130 forces fluid 124 through check valve 134 and into chamber 126to extend rams 106 and 108. If the fluid pressure is insufficient tofully support the weight exerted by vehicle 12, check valve 134 helpsprevent cylinder assembly 104 from collapsing or retracting in responseto cargo or forklift weight being added to vehicle 12.

In other examples, system 128 may be provided with fluid pressuresufficient to apply a substantially large force (e.g., vertical upwardforce) against the vehicle 12 (e.g., to actually lift the rear ofvehicle 12). Such a system would provide greater frictional holdingforce to inhibit or prevent vehicle 12 from accidentally pulling awayfrom dock 112. To further prevent pull-away, cylinder assembly 104 maybe provided with a locking mechanism (e.g., as shown in FIG. 1) tosecure the cylinder to an underside rail of vehicle 12 such as, forexample, rail 28 of FIG. 1.

Moreover, such a system could be used to raise the rear edge of vehicle12 so that the vehicle's truck or trailer bed could be roughly alignedand preferably maintained with (e.g., substantially aligned with) theelevation of the dock's platform 140. The strength and intended functionof the “bogey rail” (e.g., rail 28 of FIG. 1) described above (i.e., tosupport the weight of the loaded trailer box and react/convey forcesthereon) provides adequate strength to allow a brace to exert asubstantial or sufficient force on the bogey rail to raise and hold thetrailer at dock height. Some known vehicle braces typically engage othersurfaces or structures of the vehicle, but their upward holding force islimited in order to prevent damage to the vehicle's trailer. Such wouldnot be the case if a brace were applied to the bogy rail, while thetrailer is lifted and held fixed at dock height.

At least some of the aforementioned examples include one or morefeatures and/or benefits including, but not limited to, the following:

In some examples, an elongate member anchored at a loading dockrestrains a vehicle at the dock by attaching to a rail that is on theunderside of the vehicle.

In some examples, a vehicle restraint restrains a vehicle at a loadingdock by engaging a rail that is normally used for adjusting the positionof the vehicle's rear wheels. The restraint can clamp onto the rail, orthe restraint might include a pin that engages one of a series of holesin the rail.

In some examples, a vehicle restraint restrains a vehicle at a loadingdock by engaging a rail that runs lengthwise along the vehicle's supportframe. The restraint can clamp or latch onto the rail. The restraint,for example, might include a pin that engages a hole in the rail.

In some examples, a telescoping elongate member restrains a vehicle at aloading dock by engaging a rail that runs lengthwise along the vehicle'ssupport frame and is a part thereof. The elongate member can clamp orlatch onto the rail. The restraint, for example, might include a pinthat engages a hole in the rail.

In some examples, the elongate member includes a feature such as a slotthat allows some play or relative movement between the vehicle and theloading dock, thereby facilitating the engagement and disengagement ofthe elongate member.

In some examples, a manually operable elongate member for restraining avehicle at a loading dock includes an electric sensor for determiningwhether the vehicle is actually restrained or released.

In some examples, the elongate member has an adjustable length betweenan engagement end that is to engage a vehicle to restrain the vehicleand an anchored end that is pivotally coupled to the loading dock.

In some examples, a vehicle restraint retains a vehicle at a loadingdock by selectively pivoting an elongate member coupled to the vehicleto engage an anchor point associated with the loading dock. The anchorpoint, for example, may include a wheel guide rail.

In some examples, the elongate member is pivotally coupled to a vehicleand powered via an actuator supported by the vehicle. The actuator movesthe elongate member between a release position and a holding position toengage an anchor point such as an elevated wheel guide rail fastened toa driveway of a loading dock.

In some examples, a vehicle restraint includes a hydraulic cylinderhaving an upper and lower ram coupled to an arm such that the armadjusts the position of the hydraulic cylinder relative to the vehicle.The upper and lower portions of the hydraulic cylinder are selectivelyconfigured between a holding position and a release position. In theholding position, for example, the upper rams engage a rail portion ofthe vehicle and the lower rams engage a supporting surface. While in theholding position, the vehicle restraint prevents downward deflection ofthe vehicle. Additionally, when in the holding position, the vehiclerestraint may act as a brace that exerts a substantial force on thevehicle rail to raise and hold a rear portion of the vehicle so that abed of the rear portion of the vehicle is substantially aligned with adock platform.

Although the invention is described with respect to a preferredembodiment, modifications thereto will be apparent to those of ordinaryskill in the art. The scope of the invention, therefore, is to bedetermined by reference to the following claims:

1. A restraint for restraining a vehicle at a loading dock, wherein thevehicle includes a rail interposed laterally between a pair of wheels ofthe vehicle, wherein the rail runs generally perpendicular to arotational axis of the wheels, the restraint comprising: an elongatemember that includes an engagement end and an anchored end, the anchoredend is adapted to fasten to the loading dock, the engagement end isadapted to fasten to the rail such that when the engagement end isattached to the rail and the anchored end is attached to the loadingdock, the restraint restrains the vehicle at the loading dock, and whenat least one of the engagement end and the anchored end is detached fromits respective point of attachment, the vehicle is unrestrained by therestraint.
 2. The restraint of claim 1, wherein the engagement end isadapted to selectively engage one of a plurality of holes in the rail.3. The restraint of claim 1, wherein the elongate member has anadjustable length between the engagement end and the anchored end. 4.The restraint of claim 1, wherein the elongate member comprises a pairof telescoping members.
 5. The restraint of claim 4, further comprisinga pin coupling the pair of telescoping members to each other at variouspositions to vary an adjustable length of the elongate member.
 6. Therestraint of claim 1, wherein the elongate member includes a pin adaptedto fit within a hole in the rail.
 7. The restraint of claim 1, furthercomprising a pivotal joint at the anchored end.
 8. The restraint ofclaim 1, further comprising a clamp at the engagement end, wherein theclamp is adapted to grip the rail.
 9. The restraint of claim 1, furthercomprising a sensor detecting whether the engagement end is attached tothe rail, wherein the sensor provides a signal indicating whether theengagement end is attached to the rail.
 10. The restraint of claim 1,further comprising a sensor detecting whether the engagement end isseparated from the rail, wherein the sensor provides a signal indicatingwhether the engagement end is separated from the rail.
 11. A restraintsystem for restraining a vehicle at a loading dock, wherein the vehicleincludes a rail interposed laterally between a pair of wheels of thevehicle, and the rail defines a series of holes that facilitatesrepositioning the pair of wheels relative to the rail, the restraintsystem comprising: an elongate member that includes an engagement endand an anchored end, the anchored end being adapted to be pivotallyfastened to the loading dock; and a pin extending from the engagementend of the elongate member, the pin being selectively insertable in achosen hole of the plurality of holes such that when the pin is insertedin the chosen hole, the vehicle is restrained at the loading dock, andwhen the pin is removed from the plurality of holes, the vehicle isunrestrained by the restraint system.
 12. The restraint of claim 11,wherein the elongate member has an adjustable length between theengagement end and the anchored end.
 13. The restraint of claim 11,wherein the elongate member comprises a pair of telescoping members. 14.The restraint of claim 13, further comprising a second pin coupling thepair of telescoping members to each other at various positions to varyan adjustable length of the elongate member.
 15. The restraint of claim11, further comprising a sensor to detect whether the engagement end isattached to the rail, wherein the sensor provides a signal to indicatewhether the engagement end is attached to the rail.
 16. The restraint ofclaim 11, further comprising a sensor to detect whether the engagementend is detached from the rail, wherein the sensor provides a signalindicating whether the engagement end is detached from the rail.
 17. Amethod of restraining a vehicle relative to an anchor point at a loadingdock, wherein the vehicle includes a rail interposed laterally between apair of wheels of the vehicle, wherein the rail runs generallyperpendicular to a rotational axis of the wheels, the method comprising:selectively securing an anchor to a first location; coupling an anchorend of an elongate member to the anchor; releasably coupling anengagement end of the elongate member to the rail of the vehicle toprevent movement of the vehicle relative to the loading dock.
 18. Themethod of claim 17, further comprising inserting a pin extending fromthe elongate member into a hole in the rail.
 19. The method of claim 17,further comprising clamping the engagement end of the elongate member tothe rail.
 20. The method of claim 17, further comprising adjusting alength of the elongate member.
 21. The method of claim 17, furthercomprising pivotally coupling the elongate member relative to the anchorpoint.
 22. The method of claim 17, wherein the first location comprisesa dock wall or a driveway surface.
 23. The method of claim 17, furthercomprising: sensing whether the elongate member is engaging the rail;and providing a signal in response to sensing that the elongate memberis engaging the rail.
 24. A restraint for restraining a vehicle at aloading dock, comprising: an anchor point associated with the loadingdock; and an elongate member attached to the vehicle and beingselectively pivotal between a release position and a holding positionsuch that: a) in the holding position, the elongate member extends fromthe vehicle and engages the anchor point to help hold the vehicle at theloading dock, and b) in the release position, the elongate member issupported by the vehicle but is disengaged from the anchor point toallow the vehicle and the elongate member to depart the loading dock.25. The restraint of claim 24, wherein the elongate member has anadjustable length.
 25. The restraint of claim 25, wherein the elongatemember comprises two telescoping members.
 26. The restraint of claim 24,further comprising an elevated wheel guide rail fastened to a drivewayof the loading dock, wherein the anchor point is disposed on theelevated wheel guide rail.
 27. The restraint of claim 24, furthercomprising a powered actuator supported by the vehicle and coupled tothe elongate member, wherein the powered actuator moves the elongatemember between the release position and the holding position.
 28. Therestraint of claim 27, wherein the elongate helps support the weight ofthe vehicle when the elongate member is in the holding position.
 29. Arestraint for restraining a vehicle at a loading dock, comprising: ahydraulic cylinder comprising an upper ram and a lower ram; an armsupporting the hydraulic cylinder and being attachable to the loadingdock such that the arm can be used for adjusting the position of thehydraulic cylinder relative to the vehicle, the hydraulic cylinder isselectively configurable to a holding position and a release positionsuch that a) in the holding position, the hydraulic cylinder isunderneath the vehicle with the upper ram engaging the vehicle and thelower ram engaging a driveway of the loading dock; and b) in the releaseposition, the upper ram is spaced apart from the vehicle, and the lowerram is spaced apart from the driveway.
 30. The restraint of claim 29,wherein the arm pivotally couples to the loading dock so that thehydraulic cylinder can be swung out from underneath the vehicle.
 31. Therestraint of claim 29, wherein the arm contains a hydraulic fluid foractuating the hydraulic cylinder.
 32. The restraint of claim 29, whereinthe hydraulic cylinder prevents downward deflection of the vehicle whenthe hydraulic cylinder is in the holding position.
 33. The restraint ofclaim 29, wherein the hydraulic cylinder is to lift a rear portion ofthe vehicle so that a bed of the rear portion of the vehicle issubstantially aligned with a loading dock platform when the hydrauliccylinder is in the holding position.